<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        //sessionStorage 会话存储，当前窗口有效
        //localStorage 持久化存储，永远有效，只要不删除
        // function add() {
        //     sessionStorage.setItem("user","{'name':'zs','age':18}")
        // }
        // function del() {
        //     sessionStorage.removeItem("user")
        // }
        // function update() {
        //     sessionStorage.setItem("user","{'name':'ls','age':18}")
        // }
        // function get() {
        //     alert(sessionStorage.getItem("user"));
        // }
        function add() {
            localStorage.setItem("user","{'name':'zs','age':18}")
        }
        function del() {
            localStorage.removeItem("user")
        }
        function update() {
            localStorage.setItem("user","{'name':'ls','age':18}")
        }
        function get() {
            alert(localStorage.getItem("user"));
        }
        function createUuid(){
            var s = [];
            var hexDigits = "0123456789abcdefghi";
            for (var i = 0; i < 36; i++) {
                s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
            }
            s[14] = "4"; // bits 12-15 of the time_hi_and_version field to 0010
            s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1); // bits 6-7 of the clock_seq_hi_and_reserved to 01
            s[8] = s[13] = s[18] = s[23] = "-";

            var uuid = s.join("");
            return uuid;
        }

        console.log(createUuid())
        console.log(createUuid())
        console.log(createUuid())
    </script>
</head>
<body>
<input type="button" value="add" onclick="add()">
<input type="button" value="del" onclick="del()">
<input type="button" value="update" onclick="update()">
<input type="button" value="get" onclick="get()">
</body>
</html>